1. Field of the Invention
The present invention relates to a pluggable cage, and more particularly to a stacked pluggable cage having intermediate walls interlocked with each other.
2. Description of Related Art
A standard in development for a next generation of SFP (Small Form-Factor Pluggable transceiver) module, presently being called the XFP (10 Gigabit Small Form-Factor Pluggable transceiver) standard, calls for the transceiver modules to carry data signals at rates up to 10 Gbps.
U.S. Pat. No. 6,972,968 issued to Hwang on Jun. 22, 2004 and U.S. Pat. No. 6,731,519 issued to Hwang on May 4, 2004 discloses an SFP cage. The SFP cage comprises stacked upper and lower ports and a spacer sandwiched between the upper and lower ports. Each port has a top wall, a pair of side walls and a bottom wall connected together to surround the port.
A spacer is provided between bottom wall of the upper port and a top wall of the lower port would result in material wasted. Additionally, it is hard to achieve improved EMI (Electro Magnetic Interference) shielding since the spacer would not electrically engage the transceiver.
U.S. Pat. No. 6,752,663 issued on Jun. 22, 2004 discloses a pluggable cage having one port comprises a receptacle for receiving a transceiver. The receptacle has an upper wall, a bottom wall defining a bottom opening, a pair of side walls, a wall and a receiving cavity defined therebetween. A shielding member including a plurality of fingers is mounted to a rear edge of the bottom wall, with the plurality of fingers projecting inwardly for touching with the inserted transceiver to improve EMI performance.
When the pluggable cage has more than two stacked ports and is adapted for receiving corresponding number of transceivers, the shielding member mounted on the bottom wall could not provide EMI shielding performance to the transceiver away from the bottom wall.
Hence, a stacked pluggable cage having an improved intermediate wall is highly desired.